## Changelog since v1.13.5

### Other notable changes

* Connections from Pods to Services with 0 endpoints will now ICMP reject immediately, rather than blackhole and timeout. ([#72534](https://github.com/kubernetes/kubernetes/pull/72534), [@thockin](https://github.com/thockin))

- [`KTIJ-24476`](https://youtrack.jetbrains.com/issue/KTIJ-24476) Make application services to be classes instead of objects
- [`KTIJ-24574`](https://youtrack.jetbrains.com/issue/KTIJ-24574) K2 IDE: "No fir element was found for" from inspections

IPv4/IPv6 dual-stack has been reimplemented for 1.20 to support dual-stack Services, based on user and community feedback. If your cluster has dual-stack enabled, you can create Services which can use IPv4, IPv6, or both, and you can change this setting for existing Services. Details are available in updated [IPv4/IPv6 dual-stack docs](https://docs.k8s.io/concepts/services-networking/dual-stack/), which cover the nuanced array of options.

### Avoiding Collisions in IP allocation to Services

Kubernetes 1.24 introduced a new opt-in feature that allows you to
[soft-reserve a range for static IP address assignments](https://kubernetes.io/docs/concepts/services-networking/service/#service-ip-static-sub-range)
to Services.
With the manual enablement of this feature, the cluster will prefer automatic assignment from

- The conformance tests:
  - Services should serve multiport endpoints from pods
  - Services should serve a basic endpoint from pods
  were only validating the API objects, not performing any validation on the actual Services implementation.

The use of dual-stack networking is not mandatory.
Although clusters are enabled to support dual-stack networking, Pods and Services continue to default to single-stack.
To use dual-stack networking: Kubernetes nodes have routable IPv4/IPv6 network interfaces, a dual-stack capable CNI network plugin is used, Pods are configured to be dual-stack and Services have their `.spec.ipFamilyPolicy` field set to either `PreferDualStack` or `RequireDualStack`.

readiness changes (https://github.com/kubernetes/kubernetes/issues/111539). The service controller (in cloud-controller-manager) will avoid resyncing nodes which are transitioning between `Ready` / `NotReady` (only for ETP=Local Services).  The LBs used for these services will solely rely on the health check probe defined by the `healthCheckNodePort` to determine if a particular node is to be used for traffic load balancing. ([#109706](https://github.com/kubernetes/kubernetes/pull/109706), [@alex...

  // as the clusterIP.
  // "ExternalName" aliases this service to the specified externalName.
  // Several other fields do not apply to ExternalName services.
  // More info: https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services-service-types
  // +optional
  optional string type = 4;

  // externalIPs is a list of IP addresses for which nodes in the cluster

* Properly manage security groups for loadbalancer services on OpenStack. ([#65373](https://github.com/kubernetes/kubernetes/pull/65373), [@multi-io](https://github.com/multi-io))

* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))
* Properly manage security groups for loadbalancer services on OpenStack. ([#65373](https://github.com/kubernetes/kubernetes/pull/65373), [@multi-io](https://github.com/multi-io))